#app {
  width: 100%;
  height: 100%;
  position: relative;
}
#app img {
  width: 100%;
  display: block;
}
#app .mask {
  position: absolute;
  top: 0;
}
#app .img-t {
  position: absolute;
  top: 170px;
  left: 480px;
}
